1. Field of the Invention
This invention relates to an electromagnetic switching apparatus, and more particularly to a contactor, comprising, in a housing formed by a base and an insulating casing, a contact holder in which are housed contact bridges featuring a moving lock capable of locking the contact holder.
The contactors are equipped with contact holders fitted with contact bridges which establish or cut the current when the contact holder is moved by the moving parts of an electromagnet.
2. Discussion of Background
It is known to equip switching apparatus or contactors with locks which can lock the contact holder (e.g., refer to the patent DE 2 549 593, the patent application DE 34 02 836, or the patent DE 43 41 330).
The patent DE 43 41 330 discloses a switching apparatus featuring a contact holder lock fitted with a stop, which co-operates with a stop of the arcing casing, and a spring acting on the contact holder lock. When the arcing casing is removed, the stop is freed and the spring can move the lock from the rest position to the locked position. It is nevertheless possible to remove the casing even though the lock is jammed and cannot move to lock the contact holder. Furthermore, if the contactor is welded, a single ramp system allows the casing to be removed while the poles are established.